1. Field of the Invention
The present invention relates to a digital camera for electronically recording an image, a composition correction device for subjecting an image captured by the digital camera to composition correction processing, and a composition correction method.
2. Related Art
A digital camera, which electronically records an image, allows easy correction or modification of the image captured through image capturing operation. Hence, the digital camera is currently in wide use. One of image correction operations performed by the digital camera is correction of a composition.
For instance, a recording range of a captured image is essentially rectangular. A common photograph is preferably captured with a composition where a longer or shorter side of the rectangular area is likened to a horizontal line and a subject stands in an erect position in relation to the longer or shorter side. Consequently, in ordinary cases, a photographer performs image capturing operation while visually ascertaining the angle of the subject within a viewfinder in such way that the above composition is achieved. However, in this case, a determination as to whether or not the subject stands in an erect position is dependent on human perception. Hence, the determination is not necessarily accurate. Moreover, when the image of a moving object, or the like, is hastily captured, such a composition cannot be ascertained in detail. Consequently, there may be a case where the image of the subject is captured in a non-erect position or with a composition which is not originally intended by the photographer. In such a case, there has already been known a method for correcting the captured image by means of rotating the image such that the subject stands in an erect position.
For instance, Japanese Patent Laid-Open Publication No. 2003-219239 discloses a camera which detects the attitude of the camera during image capturing by means of an attitude sensor provided in the camera; and which rotates the captured image in accordance with the detected attitude angle. In this camera, an image capture area where an image is actually captured is made slightly larger than a recording area which is to be recorded as a captured image. Therefore, even when a captured image is rotated, a missing portion is prevented from arising in the image in the recording area. Such a camera enables capture of an image of an erect subject even when the image of the subject has been captured with the camera being tilted.
However, the technique described in Japanese Patent Laid-Open Publication No. 2003-219239 encounters a problem of a reduction in the number of pixels of a captured image as compared with the number of pixels originally captured by the camera. Specifically, the recording area of a recording image is made smaller than the image capture area. Therefore, Japanese Patent Laid-Open Publication No. 2003-219239 presents a problem of a finally-captured image being of lower definition than an image captured in a case where the image capture area is made equal to the recording area. Put another way, the technique disclosed in the Patent Publication raises a problem of an inability to sufficiently utilize the performance of the camera.